Here are some considerations to think about re-chambering or setting back already chambered barrels.
1. Factory barrels generally are not very high quality in comparison to custom aftermarket barrels.
2. With factory sporter barrels the cylinder sections are minimal in length and gives little chamber support when shortened.
3. When most factory barrels were set up for chambering they rarely are dialed in like a gunsmith would do it. They are done in mass production and the tooling is subject to have more wear in vital areas. Often the chambers are not as precise as those done one off. The throats are long to accommodate many bullet lengths.
4. The number of rounds fired in a barrel has a cumulative effect on barrels. The throat and first 8 inches of a barrel take a majority of the heat and pressure. The last 4-5 inches of the barrel take the friction of the bullet passing over it with the maximum pressure. When examining a used barrel clean it well and hold it up to the light. New barrels will have a marks on top of the lands. Shot barrels the tops of the lands will look flattened.
5. High quality barrels are lapped to both take out tool marks and to put choke into the barrel. Set back barrels are often shortened. Shortening a barrel may remove some or all of the choke.
6. To re-chamber or set a barrel back it often takes the person doing the work more time than doing an original chambering. It requires removing some or all of the previous chamber. It is more difficult to dial in due to wear in the new throat area.
6. If you are starting off with an inferior barrel don't expect it to be any better the second time around.
In years past benchrest shooters often set barrels back every 500-600 rounds. Many of them did their own work so the expense was not a factor.
I prefer not to rechamber or set back barrels because I feel in most cases it is not cost effective.
There are exceptions to this but. The aforementioned factors generally apply.
Nat Lambeth
1. Factory barrels generally are not very high quality in comparison to custom aftermarket barrels.
2. With factory sporter barrels the cylinder sections are minimal in length and gives little chamber support when shortened.
3. When most factory barrels were set up for chambering they rarely are dialed in like a gunsmith would do it. They are done in mass production and the tooling is subject to have more wear in vital areas. Often the chambers are not as precise as those done one off. The throats are long to accommodate many bullet lengths.
4. The number of rounds fired in a barrel has a cumulative effect on barrels. The throat and first 8 inches of a barrel take a majority of the heat and pressure. The last 4-5 inches of the barrel take the friction of the bullet passing over it with the maximum pressure. When examining a used barrel clean it well and hold it up to the light. New barrels will have a marks on top of the lands. Shot barrels the tops of the lands will look flattened.
5. High quality barrels are lapped to both take out tool marks and to put choke into the barrel. Set back barrels are often shortened. Shortening a barrel may remove some or all of the choke.
6. To re-chamber or set a barrel back it often takes the person doing the work more time than doing an original chambering. It requires removing some or all of the previous chamber. It is more difficult to dial in due to wear in the new throat area.
6. If you are starting off with an inferior barrel don't expect it to be any better the second time around.
In years past benchrest shooters often set barrels back every 500-600 rounds. Many of them did their own work so the expense was not a factor.
I prefer not to rechamber or set back barrels because I feel in most cases it is not cost effective.
There are exceptions to this but. The aforementioned factors generally apply.
Nat Lambeth
